INDIANAPOLIS — Even a chore as mundane as packing a suitcase feels different now to Helio Castroneves. He says he relishes the freedom to go where and when he wants, the freedom to wedge himself into the cockpit of an Indy car and drive it without lifting the gas pedal.

Castroneves turned 34 on May 10, but he now tells everyone that he was celebrating his first birthday. Three weeks earlier, Castroneves, his sister Kati and his lawyer Alan Miller were acquitted of federal income-tax charges in Miami, and it was as if he were starting over.

“You appreciate things you normally don’t,” Castroneves said. “I knew how much I loved to race, but after that happened, I know this is the place I believe I need to be. This is the place where I know what to do.”

Castroneves, the happy-go-lucky Brazilian, will start from the pole position today for the Indianapolis 500, a race he won twice before he widened his appeal in November 2007 by winning the fifth season of ABC’s “Dancing with the Stars.”

As one of three drivers for the formidable race team owned by Roger Penske, Castroneves has a strong opportunity to win his first Indy 500 in seven years. He is sunnier and chattier than ever, at least publicly.

His trial lasted six weeks, and Castroneves shut himself off from the world, losing weight from his small frame and spending most of his time on the Internet. He was away from racing for more than six months, returning for an April 19 race in Long Beach.

“He matured a lot,” said Tim Cindric, the president of Penske Racing. “The guy who is here this year, compared to the guy who was here last year, has a different maturity level. Not so much behind the wheel, but in his overall perspective on life.”

Castroneves and his sister turned themselves in to federal authorities in Miami on Oct. 3. He returned to Atlanta the next day and met with Cindric and other members of the team. As they were talking, Cindric said, the television showed a clip of Castroneves in shackles, crying into a handkerchief. Castroneves tried to lighten the mood by pointing at the screen and exclaiming: “Look! I’m on TV!”

“That was probably the last joke he told for a while,” Cindric said.

Castroneves, his sister and Miller faced six-year prison sentences. According to the Associated Press, the Internal Revenue Service claimed the three plotted to evade about $2.3 million in taxes by using a shell corporation in Panama and supposedly crooked dealings with the Brazilian firm Coimex, a former sponsor of Castroneves’.

Team Penske moved on, hiring Will Power. Cindric said it was made clear that Castroneves would resume driving for Penske if he were acquitted, but the team, and a series, braced for time without one of its most charismatic stars.

“He’s one of our most recognized drivers,” said Scott Dixon, who won the Indy 500 last year. “Just by winning ‘Dancing with the Stars,’ he brought a huge benefit to IndyCar racing. He’s always an upbeat guy, very positive — which is more than what you can say about most of us.”

Power replaced Castroneves for the season-opening race April 5 in St. Petersburg, Fla. When Castroneves was acquitted of six counts of tax evasion after six days of deliberation (federal authorities dropped a tax-evasion conspiracy charge Friday), he was free to race again.

Terry Angstadt, the president of the commercial division of the IndyCar Series, said last week: “I’m so happy for him. Our business would have survived. But you can just see what an infectious personality he is.”

Castroneves replaced Power, who was given another car by Penske.

Castroneves came in seventh at Long Beach, finished second to Dixon a week later in Kansas City, Kan., then posted the fastest qualifying speed for the Indianapolis 500, covering four laps at a speed of 224.864 mph.

He was the fastest driver in the final practice session Friday at Indianapolis Motor Speedway.

“It’s like he never left,” said his teammate Ryan Briscoe, who will start second.

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